360 was originally conceived for 1971 model year as a lighter, more economical alternative to the 383 in C-bodies which were Mopar's biggest volume sellers at the time. Bigger mains from the start were to improve crank fatigue life due to the longer stroke (in theory). Iirc 1972 they started being offered in trucks, my '72 D200 has a factory 360. They work well in that application, tons of grunt and has the driving feel of a big block. Drinks gas like one too lmao.